Synthesis of N, P-doped C@Mo₂C catalyst and its application in CO₂ hydrogenation

The N, P-doped C@Mo₂C catalysts were prepared using melamine benzoate as the source of nitrogen and carbon, melamine phosphomolybdate as the source of phosphorus, nitrogen and molybdenum, respectively. The surface structures of the prepared catalysts were characterized by XRD, SEM, TEM and XPS. The effects of the ratio of benzoic acid to melamine in melamine benzoate and n(C)/n(Mo) of the precursor on the catalysts were investigated. The activity of the catalysts was evaluated by using CO₂ hydrogenation as a model reaction in a fixed-bed reactor, in which a mixed gas of CO₂/H₂ (V_H2:V_CO2=3:1) was used as the feed gas, and it was found that the N, P-doped C@Mo₂C showed a good catalytic performance with CO₂ conversion of 12.2% and methanol selectivity of 52.2% under the optimal reaction conditions (reaction temperature 220℃, reaction pressure 3.0 MPa, space velocity 3 600 mL/(g·h).